1. Field of the Invention
The present invention relates to a gas tube structure, and more particularly to a gas tube for connection of a metallic gas tube, a gas barrel, a gas stove or a water heater. The gas tube is used to connect the metallic gas tube/gas barrel and the gas stove/water heater.
2. Description of the Prior Art
A soft gas tube is used to connect a metallic gas tube/gas barrel and a gas stove/water heater. For lock, the end of soft gas tube is rotatable. In U.S. Pat. No. 5,553,893 as shown in FIG. 5, the end of a flexible tube 10 is provided with a fastening ring 20. The fastening ring 20 is connected with a fixed connector 30. The fixed connector 30 is connected with a movable connector 40. The flexible tube 10 includes a metallic tube layer 11, a metallic net layer 12 and a plastic tube layer 13 which are stacked from inside to outside in sequence. The fastening ring 20 is made of metal. The fixed connector 30 is made of metal and has a central through hole 31. The inner end of the fixed connector 30 is welded to the end of the flexible tube 10. The outer end of the fixed connector 30 has a connection section 32. The connection section 32 has a groove 33 and a plurality of seal grooves 34. The groove 33 is adapted to receive a C-shaped buckle 35. The seal grooves 34 are adapted to receive seal rings 36. Each seal ring 36 has a circular cross-section. The movable connector 40 has a central hole 41. One end of the central hole 41 has a receiving hole 42, a fastening groove 43 formed in the receiving hole 42. The other end of the movable connector 40 has a lock section 44 to connect the connector of the gas stove and the water heater.
The C-shaped buckle 35 is connected between the fixed connector 30 and the movable connector 40. The C-shaped buckle 35 has a gap, which may be deformed easily and is not strong enough. The C-shaped buckle 35 may be pulled away by accident, so it is not safe for use. The fastening ring 20 is welded to the fixed connector 30 to form a weld point A. This way consumes manpower and increases cost. The weld point is exposed to result in a crack and cannot be used.
In U.S. Pat. No. 6,742,815 B2 as shown in FIG. 6, the metallic tube layer 11 extends in the fixed connector 30 to connect with the inner end of the movable connector 40. The plastic tube layer 13 is fixed to the outer edge of the distal end of the fixed connector 30 by the fastening ring 20. The C-shaped buckle 35 is used to connect the movable connector 40. This structure is complicated and is difficult to assemble. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.